setSafeVars example

    private function isSafeFor(string $type, Node $expression, Environment $env): bool
    {
        $safe = $this->safeAnalysis->getSafe($expression);

        if (null === $safe) {
            if (null === $this->traverser) {
                $this->traverser = new NodeTraverser($env, [$this->safeAnalysis]);
            }

            $this->safeAnalysis->setSafeVars($this->safeVars);

            $this->traverser->traverse($expression);
            $safe = $this->safeAnalysis->getSafe($expression);
        }

        return \in_array($type, $safe) || \in_array('all', $safe);
    }

    private function needEscaping(Environment $env)
    {
        if (\count($this->statusStack)) {